The princiipal investigator and lead investigator retired this year. No report Work has continued on the NMR characterization of oligosaccharide intermediates of Vibrio cholera antigens, including saccharides up to the decamer level of complexity. The techniques used included high-resolution one-dimensional (1D) H-1 and 1D C-13 NMR at 500 MHz and 126 MHz, respectively. Validation of the chemical structures was based on integration of the 1D H-1 NMR spectra, and on counting of carbon resonances in the 13C spectra, especially in the well-separated spectral regions of the C=O, aromatic C, C-1, C-N, and C-CH3 moieties. The NMR spectra were also used to assess the purity of the synthetic preparations, for example, determination of the extent of completion of hydrogenolytic removal of benzyl protecting groups by measurement of the content of aromatic groups.